Snack and cereal bars are becoming more popular with consumers for their ease in providing a convenient and ready-to-eat product. Common snack and cereal bars typically tend to be either crunchy or chewy. The crunchy bars generally have a low water activity less than about 0.5 and, in some cases, around 0.2 to about 0.3. Chewy bars generally have a higher water activity typically greater than about 0.5 and, in many cases, between about 0.5 to about 0.65. Such chewy bars can, in some instances, be more desired because they resemble the texture and mouthfeel of candy bars. To achieve this chewy texture, such bars may use high levels of a binder component relative to the other bar ingredients, where the binder component helps provide a moist and chewy texture while at the same time holds the various bar ingredients, such as granola, grains, fruit, nuts and the like together in a cohesive bar shape. The binder component acts as a glue to retain the bar in the desired shape. To achieve the chewy texture, however, many prior snack and cereal bars, similar to many candy bars, use relatively high amounts of sugar syrups, humectants, gums, glycerin, and/or other sugar based binding ingredients as one of the main components of the binder. The sugar syrups, such as corn syrup, isomalt, maltitol, maltose syrups, and the like, can be useful for forming a moist and chewy bar due to a humectant effect of these syrups, which tends to retain moisture in the bar. However, such sugar syrups, gums, humectants, and/or glycerin are generally less desired in foods for a number of reasons.
Without such binder ingredients in a bar to provide the humectant effect, simply increasing the moisture level or water content of the binder in order to increase the bar's chewiness or moistness can render manufacturing of the snack or cereal bar difficult on conventional bar processing equipment. Moreover, high moisture binders without these traditional binding ingredients may completely fail to form a self-supporting bar because the binder cannot retain the bar in a desired shape. Conventional bar making equipment commonly includes compression rollers to sheet out a slab of dough, slitting knives to cut the sheeted dough into a desired width, and guillotine blades to cut the slit dough into a desired length. By increasing the moisture level of a binder without the use of syrups, gums, humectants, or other sugar based binders, the higher moisture binder often cannot effectively retain a sufficiently firm slab for processing on such equipment. In other instances, the increased moisture dough may be too sticky on its outer surfaces, which may cause problems when the bar is processed through the compression rollers, slitter knives, and guillotine blades because the bar dough may ball-up or pick-off onto the equipment.
Attempts have also been made to employ alternative binders, such as dairy-based binding components, but prior dairy-based binders have shortcomings that render the dairy binders less than desirable for a number of reasons. For example, prior snack bars with dairy-based binders generally have a lower moisture level resulting in a crispy texture, employ humectants or sugar syrups to maintain higher moisture levels, add gums to achieve sufficient binding capacity, and/or require high processing temperatures to functionalize the dairy proteins into an effective binder component. These all tend to be shortcomings of a dairy-based binder. As mentioned above, crispy bars generally do not provide the mouthfeel and eating satisfaction that chewy bars can provide. While high levels of humectants, sugar syrups, and/or gums may be effective in forming a self-supporting, chewy bar with dairy-based binders, as discussed above, these ingredients are generally less desired in foods. High processing temperatures, which are believed to be needed to functionalize a dairy ingredient into an effective binder, can have negative organoleptic effects on the dairy components resulting in undesired organoleptic changes such as a cooked flavor, burnt notes, agglomeration, and/or a gritty texture of the finished bar. Cooked or burnt flavor notes takes away from the fresh dairy impression upon eating.
When using large amounts of a dairy source as a binder, it is generally believed that heating or cooking the dairy ingredients at temperatures of at least about 70° C. (158° F.) or higher may be needed in order to functionalize the dairy proteins as a binder component. While not wishing to be limited by theory, it is generally believed that heating dairy proteins helps solublize or disperse casein proteins into an aqueous phase, which then results in an increase in viscosity of the binder and a much firmer bar. It is generally believed that the solublized dairy proteins can more easily mix with various additives and form bonds on a molecular level to help bind various materials together.
However, as mentioned above, heating at such high temperatures needed to functionalize the dairy is generally undesired. For example, heating a dairy-based binder to about 70° C. (158° F.) or above generally causes the lactose in the dairy binder to be solubilized. Upon cooling of the bar, it is believed that the lactose may solidify into crystals that can form into relatively large agglomerates upon cooling. Such large crystals or agglomerates may result in a gritty mouthfeel or a bar that does not have texturally smooth or creamy characteristics.
Prior cereal bars employing a dairy-based binder also incorporated gums, humectants, hydrocolloids, glycerin, and sugar syrups in order to achieve a chewy or creamy mouthfeel. Use of large amounts of these ingredients is also generally undesired. These ingredients can be high in sugar and calories and/or impart undesired sweetness and other unwanted organoleptic characteristics to the bar.
Also, exposing dairy ingredients to high temperatures above about 70° C. (158° F.) also may result in an off-white color to the dairy components due to discoloration of the dairy components in the binder due to the heating. For example, dairy proteins typically undergo browning reactions upon exposure to elevated temperatures. Heating dairy proteins may result in color changes and/or gelation during processing or extended storage. It is believed that the lactose in milk, which has been heated to high temperatures, tends to interact with proteins and results in an unsightly brown color. This undesired condition is often referred to as “browning” or a “browning reaction.” Both gelation and browning are undesirable in milk and products using dairy proteins since they impart objectionable organoleptic properties and negatively affect the creamy and white color desired in food bars employing dairy components